• Korean Journal of Weed Science
• /
• v.15 no.3
• /
• pp.197-205
• /
• 1995

The objectives of the present study were to find out 1)the differences in growth of radish under foggy and non-foggy condition, 2)the weed competition between radish and major upland weeds including Echinochloa crus-galli, 3)difference in response of radish to herbicide and weed, and finally 4)the fundamental data for the establishment of radish weed control system under locational foggy regions. The research was carried out by tray in greenhouse equipped with Auto Foggy System(SAE KI RIN Co.) and results were summarized as follows. 1. Plant height and shoot fresh weight of radish cultivars(long skirt, delicious altari, green mascot) were not different at the early growth(8 to 38 days after seeding), but increased at 55 days after seeding under foggy condition. Root fresh weight increased only in green mascot cultivar tinder foggy condition. Chlorophyll contents were higher in all the cultivars of radish under foggy condition. 2. Plant height and shoot fresh weight increased at 0 and 20 days of weed competition under foggy condition. Root fresh weight increased at 0, 20 and 35 days of competition under foggy condition. Above 50 days-competition, there was no difference between foggy and non-foggy condition. 3. Napropamide, alachlor and linuron did not show any differences in plant height and shoot fresh weight between foggy and non-foggy condition. Molinate reduced the root fresh weight at 65 days after seeding tinder foggy condition. 4. No difference in weeding efficacy by any herbicides tested was found tinder foggy condition. Weeding efficacy of Aeschynomene indica was reduced under foggy condition.

• Korean Journal of Weed Science
• /
• v.16 no.3
• /
• pp.194-199
• /
• 1996

Seed size and days required to reach specific growth stages were determined for Echinochloa crus-galli (L.) P. Beauv. varieties which are major grass species found in Korean paddy field and the results were compared with E. frumentacea (Roxb.) Link. In addition, responses of the Echinochloa species on preemergence herbicides (molinate, esprocarb, and mefenacet) were investigated with respect to time of application. One thousand seed weight of E. crus-galli var. oryzicola was about 3 times heavier than that of var. praticola, but was not significantly different that of E. frumentacea. Days requited to reach the 2.5 leaf-stage (LS) were 11, 13, and 14 days after seeding for E. frumentacea, E. crus-galli var. oryzicola, and E. crus-galli var. praticola, respectively. E. crus-galli var. praticola was more sensitive to molinate, esprocarb and mefenacet than var. oryzicola and the sensitivity of both the varieties decreased as the time of application LS was delayed. However, there was no great difference in the response for E. frumentacea when applied between 1.5 and 3.0 LS. In thiocarbamate hebicides esprocarb was more active to Echinochloa species than molinate and the higher the active ingredient of the herbicides, the greater was the activity to Echinochloa species. Differential susceptibility of Echinochloa species to the herbicides was not related to the seed size, but to the early growth stages at the time of herbicide application which were affected by the seed size.

• Korean Journal of Weed Science
• /
• v.12 no.4
• /
• pp.387-392
• /
• 1992

For reducing the residual effects of Quinclorac to followed-by crops of paddy rice, three tests by different soil improvers, different cultural performances with tillage and application of composts, and cultivation of different depletion crops were evaluated, respectively. Among seven soil improvers, activated carbon, composts and perlite showed significant promisable feasibility to reduce phytotoxicity of tomato seedlings as affected by Quinclorac residuals, And comparing to untreated check, the application of tillage and composts prior to transplanting of tomato seedling could helpful to reduce Quinclorac residuals in the soil, but tomato and lettuce, most susceptible crops to Quinclorac, were not remarkably protected by those cultural performances. Also among cultivation of depletion crops just after rice harvest, Italian ryegrass, tall fescue, rape and oats engaged to deplete and reduce Quinclorac residuals for tomato seedling growth, however alfalfa and hairy vetch, relatively susceptible plants to Quinclorac were not promisable.

• Weed & Turfgrass Science
• /
• v.7 no.3
• /
• pp.259-268
• /
• 2018

This study was conducted to evaluate the effect of liquid fertilizer containing humic acid and Saccharomyces cerevisiae broth (LHS) on changes of turfgrass growth by investigating visual quality, chlorophyll content, dry weight of clipping, and nutrient content in leaf tissues. Treatments were designed as follows; control fertilizer (CF), HS-1 ($CF+1.0mL\;m^{-2}\;LHS$), HS-2 ($CF+2.0mL\;m^{-2}\;LHS$), and HS-3 ($CF+4.0mL\;m^{-2}\;LHS$). After treatment of LHS on creeping bentgrass, soil pH in the treated plots was decreased than that of CF. As compared to CF, visual quality, chlorophyll content and content of N, P and K were not significantly different in the LHS treatments. However, clipping yield and phosphorus uptake of HS-2 were significantly increased by 22% and 33%, respectively. These results showed that application of LHS improved the phosphorus uptake and growth of creeping bentgrass, which would be an alternative management tool for the cool season turfgrass under stress conditions.

• Korean Journal of Weed Science
• /
• v.10 no.3
• /
• pp.202-206
• /
• 1990

Field experiment was conducted to develop a model of controlled release of oxyfluorfen by using various split applications. Rice and some weed species was included in this study. The models of split applications were 10-10-0. 10-10-10. 20-20-0, 20-10-10. 20-20-20, 0-40-0, and 0-0-0g/Ha at 3days before transplanting, and 11 days after transplanting, respectively. Rice injury appeared dispeared at 20 g/Ha of oxyfluorfen on low leaf sheath but disappeared at few days. The injury was reduced by split application even at the same rate of application. However, no injury was siginificant at 30 days after transplanting. Barnyardgrass, Monochoria, and arrowhead were most susceptible to oxyfluorfen, but bulruch and most perennial weeds recovered after temporary growth inhibition. Therefore, to develop oxyflourfen for use in rice transplanting of adult rice seedling, split application with reduced rates, and development of expected to be tank-mixed or premixed with other perennial herbicides to obtain droad spectrum of weeds.

• Korean Journal of Weed Science
• /
• v.14 no.2
• /
• pp.144-155
• /
• 1994

Scanning electron micrography and Transmission electron micrography studies were performed on the surfaces of stem(coleoptiles) of rice and barnyardgrass under various cropping patterns at 5 days after seeding or transplanting. Stem surfaces of rice under dry condition possessed rodlet-like epicuticular waxes, trichomes, stomata and cork cell layer in both broadcast and drilled rice while barnyardgrass had only thread-like epicuticular waxes, but trichomes, stomata and cork cell layers were not found. However, rice under water condition has no rodlet-like waxes, stomata and cork cells, and barnyardgrass was similar to that under dry condition. On the other hand, those on stems of 8-day and 25-day transplanted rice were well arranged and developed compared with those of direct seeded rice. Electron micrography showed significant difference in thickness of outer epidermal cell walls of rice and barnyardgrass under dry, water and transplanting condition. Thickness of outer epidermal cell was greater in transplanted rice, dry direct seeded rice, water-direct seeded rice and barnyardgrass in descending order.

• Korean Journal of Weed Science
• /
• v.5 no.2
• /
• pp.143-148
• /
• 1985

Water hyacinth, unused and tropical plant was examined in order to know the feasibility of application for purification of municipal drainage and industrial wastewater. This plant was effective to remove the COD from wastewater, although its removal ability was dependent on the organic sources. The effects of pH, NaCl concentration, water temperature and shading condition on the growth of water hyacinth were investigated. The optimum ranges of pH were weak acid- neutral, of water temperature were 17-$21^{\circ}C$, and unshading condition was better. The rapid propagation of this plant was also observed during hot summer season.

• Korean Journal of Weed Science
• /
• v.14 no.4
• /
• pp.280-290
• /
• 1994

The germination and the nutrient culture tests in the growth chamber and pot experiment under two types of soil conditions were conducted to determine the selectivity of oxyfluorfen and chlormethoxynil in crops and weeds and for characterization of selective mode of action, the absorption study was also conducted with different absorption methods and application time using $^{14}C$-oxyfluorfen. Oxyfluorfen showed more growth inhibitory effects than chlormethoxynil. In the nutrient culture test, rice growth was greatly inhibited at 2-leaf stage than at 4-leaf stage, and the shoot parts were more inhibited than the root parts. By preemergence application of both herbicides, higher growth inhibition was observed in sandy loam soil than in clay loam soil. Absorption and translocation of $^{14}C$-oxyfluorfen were higher by foliar application than by root treatment, and selectivity of crops and weed species may be explained partly by the amount of absorption.

• Korean Journal of Weed Science
• /
• v.12 no.1
• /
• pp.1-7
• /
• 1992

The experiment was conducted to investigate effects of bensulfuron-methyl{methyl 2-((((((4,6-dimethoxypyrimidin-2-yl)amino)carbony)amino)sulfonyl)methyl)benzoate}on bud sprouting, percent regrowth, and regrowth from growth cessation in Eleocharis kuroguwai. Application of bensulfuron-methyl resulted in sprouts of two of three lateral buds in addition to the apical bud of E. kuroguwai. With bensulfuron-methyl the culms elongated from the sprouted buds were killed soon after emergence. However, the buds remained biologically active. During the period of growth cessation the tuber buds respired in a minimum rate, but respiration began to increase with regrowth. At regrowth increase in the respiration was greater in the lateral buds than in the apical bud. Days required to regrowth was 35 days in the suppressed apical bud when applied at the rate of 51 g a. i. ha bensulfuron-methyl, while the suppressed lateral buds sprouted first and second required 29 and 28 dyas, respectively. After regrowth number of new culms was two to three times greater in the lateral buds than in the apical bud.

• Weed & Turfgrass Science
• /
• v.3 no.2
• /
• pp.143-149
• /
• 2014

This study was conducted to evaluate the effects of the mixture ratio of soil amendments blended with coco peat (Coco) and American soldier fly cast (SFC) on the physicochemical properties on the sand green. pH and EC of soil were significantly related to mixture ratio of SFC, Mix1, Mix2 and Mix3. Capillary porosity, air-capillary porosity and total porosity of root zone mixed SFC, Coco, Mix1, Mix2 and Mix3 were met to the USGA green specification. The mixture ratios of Mix1 and Mix2 in root zone were positively related capillary porosity and total porosity, and air-capillary porosity was negatively related capillary porosity and hydraulic conductivity. Capillary porosity of Mix1, Mix2 and Mix3 blended SFC and Coco was affected by SFC and Coco, and total porosity by Coco. These results showed that soil amendments blended SFC and Coco was developed capillary porosity and hydraulic conductivity on the USGA sand green than these of SFC.